Utility model specification DE202006014743U1 discloses an apparatus in which a length of a distributor passage, which can be acted upon with fluid, is varied with a closure body driven by way of a drive device. Drive devices which are typically used have a holding device, a screwthreaded spindle mounted in the holding device, a screwthreaded body and a guide rod for the screwthreaded body. The screwthreaded body is displaced along the guide rod by rotation of the screwthreaded spindle. The screwthreaded body is connected in positively locking relationship to the closure body, whereby the movement of the screwthreaded body is transmitted to the closure body.
In a first limit position the closure body is pushed to a minimum distance into the distributor passage and the screwthreaded spindle projects over almost the entire length out of the nozzle arrangement. In a second limit position, that is, in a position in which the length of the distributor passage and the nozzle opening is at its smallest, the closure body is pushed into the distributor passage by the maximum extent. In order to ensure mobility of the closure body between those two limit positions, the screwthreaded spindle must be at least as long as the part of the closure body that projects out of the distributor passage, when the closure body is in the first limit position. As the screwthreaded spindle must be supported and requires an engagement portion at its end remote from the distributor passage so that it can be rotated, additional structural space is required for the drive device. The drive device not only requires structural space in line with the longitudinal axis of the distributor passage but also in radial relationship therewith, in particular for the holding device for mounting the screwthreaded spindle. The fact that a relatively large amount of structural space is required for the drive unit of the closure body can have a disadvantageous effect. Thus, the extent of the drive device in the longitudinal direction of the closure body can be detrimental as the drive device can collide with adjoining machines such as labelling machines or can collide with walls of a room.
Therefore the object of the invention is to provide an apparatus which makes it possible for the applicator apparatus to be of a more compact structure but at the same time does not adversely affect the displaceability of the closure body.